Standard and ϵ-finite master integrals for the ρ-parameter Original Research Article

We have constructed an ϵ-finite basis of master integrals for all new types of one-scale tadpoles which appear in the calculation of the four-loop QCD corrections to the electroweak ρ-parameter. Using transformation rules from the ϵ-finite basis to the standard “minimal-number-of-lines” basis, we obtain as a by-product analytical expressions for few leading terms of the ϵ-expansion of all members of the standard basis. The new master integrals have been computed with the help of the Padé method and by use of difference equations independently.